#2. What is Your Biome?---Coral Reef

http://www.youtube.com/watch?v=WnaW6IiF580&feature=related


Our Biome is coral reef. Coral reefs or corals may seem like a common thing, but there are many things that you probably don’t know about coral reefs. Corals are modern forms of ancient animals. During the period of about 25 million years, corals have been formed by ancient animals that existed many years ago. Some well developed coral reefs can possibly tell scientists about history. Anthozoans are the largest class of organisms in the phylum Cnidaria. Corals are anthozoans. The two things all corals have in common are the gastro vascular cavity and tentacles. Corals eat and excrete waste from their gastro vascular cavity, also known as their mouth. A circle of tentacles that surround their mouth do three things. They help corals catch plankton to eat, they clean debris from their mouth, and they use these tentacles for defense. Even though corals may seem to be very simple, they are actually pretty cool. They have a unique type of cell called nematocytes. These nematocytes deliver a powerful toxic sting. This also helps for corals to catch their prey. To make coral reefs, stony corals secrete a skeleton, CaCO3. There can be different colonies of corals.

-->What would happen if you tried to grab coral with you hand?

http://www.coris.noaa.gov/about/what_are/